But environmentalists are livid Coles is actively promoting plastic trade swaps - a direct contradiction of its wobbly-kneed stance on phasing out single-use plastic bags in Victoria, NSW, Qld and WA since July 1.

Greenpeace campaigner Zoe Deans likened the campaign to that of McDonald's Happy meals toys that the fast-food outlet has previously used to get customers through the door.

"Sadly the majority of these Little Shop toys are likely to end up in landfill sooner rather than later," she said.

"Very few people hang on to toys such as these - virtually nobody still has the McDonald's Happy Meal toys they had a child.

"Coles are fooling themselves if they think parents and children will hang on to Little Shop toys for decades to come."

The Swap Day will be held on Saturday in 35 stores nationally - or about four per cent of its stores.